GPTZero vs Originality.ai

Updated November 2026 · AppBreakup editorial

GPTZero

AI detector that estimates how much of a text was written by ChatGPT, Claude or Gemini.

Free plan + paid

Visit GPTZero GPTZero profile

Originality.ai

AI and plagiarism checker for publishers, agencies and content teams.

Free plan + paid

Visit Originality.ai Originality.ai profile

The short answer

GPTZero is built for teachers, with Google Docs, Classroom and Canvas integrations and free checks of short texts without an account. Originality.ai is built for publishers and SEO agencies, combining AI detection, plagiarism, readability and fact checks in one credit-based scan. Pick by audience: GPTZero for classrooms, Originality.ai for checking bought or freelance content.

GPTZero or Originality.ai: our take

Both tools estimate how likely a text is to be AI-written and highlight suspicious passages, and both have added plagiarism checking and a replay of how a document was typed. The difference is who they serve. GPTZero started in January 2023 as a tool for teachers worried about ChatGPT essays, and it still leans that way: it integrates with Google Docs, Google Classroom and Canvas, and its Writing Replay shows how a Google Doc was written over time as evidence of authorship. Originality.ai targets website owners, editors and marketing teams. A single scan can report AI likelihood, copied passages, readability and grammar, and flag claims that may be false.

Pricing works differently. GPTZero lets you check texts under 10,000 characters without an account; longer scans and extra tools need a free account or a paid plan, and teams can buy shared word allowances. Originality.ai runs on credits, with one credit per 100 words. The free plan is 10K words one time, not a monthly refill, and Pro starts at $14.95/month for 200K words per month. API access differs as well: GPTZero offers a developer API, while Originality.ai keeps its API to the Enterprise plan.

On platforms, both are web apps with browser extensions. GPTZero's extension is for Chrome. Originality.ai has extensions for Chrome, Firefox and Google Docs, plus a Moodle plugin for schools. GPTZero has full support for English, German, Portuguese, French and Spanish.

Teachers and schools on Google Classroom or Canvas should start with GPTZero, especially since short checks are free without signing up. Publishers and agencies reviewing freelance articles will get more from Originality.ai's combined scan and predictable cost per word. Whichever you use, treat the score as a probability, not proof: both can mislabel human writing, so a result is a reason to ask questions, not a verdict.

Choose GPTZero if…

Teachers and schools that want an AI check built into Google Docs, Classroom and Canvas
Short texts can be checked without signing up
Writing Replay shows how a document was actually typed

Choose Originality.ai if…

Publishers and SEO agencies checking freelance content for AI writing and plagiarism
AI detection, plagiarism, readability and fact checks in one scan
Credit system makes cost per word easy to predict

What is GPTZero?

GPTZero checks a piece of writing and estimates how likely it is to be AI-generated, highlighting the sentences that look machine-written. It started in early 2023 as a tool for teachers worried about ChatGPT essays and is still aimed mostly at education, with integrations for Google Docs, Google Classroom and Canvas plus a Chrome extension. Around the core detector it has added a plagiarism checker, a grammar and feedback tool, and Writing Replay, which shows how a Google Doc was typed over time as evidence of authorship. You can paste short texts without an account; longer scans and the extra tools need a free account or a paid plan, and teams can buy shared word allowances. A developer API lets schools and platforms build detection into their own products. Like every AI detector, its scores are probabilities rather than proof, so results are best used as a prompt for a conversation rather than as a verdict.

What is Originality.ai?

Originality.ai is an AI-content and plagiarism checker aimed at people who buy or publish written content: website owners, SEO agencies, editors and marketing teams. A single scan can report the chance a text was AI-written, find copied passages, score readability and grammar, and flag claims that may be false. It runs on credits, where one credit covers 100 words; a free tier gives a small one-time allowance, the Pro plan adds a monthly batch of credits, and the Enterprise plan adds API access and a year of scan history. Extensions for Chrome, Firefox and Google Docs let you scan text where you write it and watch a replay of how a document was produced, and there is a Moodle plugin for schools. It is web-based, priced in US dollars, and leans more toward publishing workflows than classroom use.

Side by side

Attribute	GPTZero	Originality.ai
Pricing	Free plan + paid	Free plan + paid
Open source	No	No
Self-hostable	No	No
Platforms	Web, Browser extension	Web, Browser extension
Best for	Teachers and schools that want an AI check built into Google Docs, Classroom and Canvas	Publishers and SEO agencies checking freelance content for AI writing and plagiarism
Status	Active	Active

Verified facts, compared

Facts both apps publish, checked on each vendor's own site.

Fact	GPTZero	Originality.ai
API	Yes	Enterprise plan